Multi-section mold with air pressure ejection ring

ABSTRACT

APPARATUS FOR PRODUCING CLAY PIGEONS INCLUDES AN IMPROVED EJECTOR RING FOR EJECTING THE CLAY PIGEONS FROM A MOLD CAVITY. IN THE APPARATUS, THE EJECTOR RINGS IS BACKED UP RIGIDLY BY A SUPPORTING PLATE DURING NORMAL OPERATION AND IS THEN MOVED BY AIR PRESSURE TO EJECT OR STRIP THE CLAY PIGEON FROM AS ASSOCIATED MOLD OR DIE SECTION WHEN THE MOLD SECTIONS SEPARATE. THE AIR ALSO IS SUPPLIED BETWEEN THE MOLD SECTION AND THE CLAY PIGEON TO ELIMINATE ANY VACUUM AND FACILITATE EJECTION OF THE CLAY PIGEON.

United States Patent Inventor Eli H. Mechling. 2881 McClain Road.

Llma,0hio

June 11, 1969 June 28, 1971 Appl. No Filed Patented MULTl-SECTION MOLD W1T1-1 AIR PRESSURE JECTION RING 8 Claims, 6 Drawing Figs.

US. Cl 25/1 18, 18/2, 25/22, 249/66 Int. Cl 132% 7/10 Field of Smrch 25/22, 23,

27, 28, 118 (R), 120; 18/2 (NA), 2 (NF); 249/66; 0

[56] References Cited UNITED STATES PATENTS l ,497, 191 6/1924 Moland 25/27 1,769,529 7/1930 Miller 25/22X 3,167,811 2/1965 Kraus et al 18/2 Primary Examiner-Robert D. Baldwin Attorney-Allen D. Gutchess, Jr.

ABSTRACT: Apparatus for producing clay pigeons includes an improved ejector ring for ejecting the clay pigeons from a mold cavity. in the apparatus, the ejector ring is backed up rigidly by a supporting plate during normal operation and is then moved by air pressure to eject or strip the clay pigeon from an associated mold or die section when the mold sections separate. The air also is supplied between the mold section and the clay pigeon to eliminate any vacuum and facilitate ejection of the clay pigeon.

PATENTED Ju-28 I971 3,587.144

SHEET 1 or 2' INVENTORZ ELI H. MEDHLINE'.

JITTYS..

FIB-Z- PATENTED JUH28|97| 335 7144 sum 2 or 2 INVENTOR: ELI HMEEHLING.

ATTYS MULTll-SECTTON MOM) Wl'lli AIR PRESSURE MECTWN RHNG The invention relates to an ejecting mechanism for a molding machine and more particularly to an ejector ring for apparatus for producing frangible flying targets.

Frangible flying targets, specifically in the form of clay pigeons, are commonly made today at high production rates on multistation forming machines. While two stations could suffice, one at which the mold cavity for the target is filled and another at which the target is removed, a large number of stations provides sufiicient dwell time for the material to harden to a self-sustainable state and yet maintain the high production rates needed for efiicient operation. Ejection of the targets from the mold cavities must be done carefully since the targets are not fully hardened at this time and can be distorted or damaged. True concentricity of the target should be maintained in order that its flight will be smooth when propelled through the air for target shooting.

The present invention provides an ejecting mechanism for a machine for forming frangible flying targets, which mechanism has a number of advantages over those heretofore known. The ejecting mechanism includes a ring located around one of the mold sections of each mold assembly of the machine. The ring is rigidly backed up by a supporting plate when the mold sections are assembled in order to enable the ring to engage and maintain maximum pressure against the other mold section, thereby reducing flash on the molded target. Air is applied as the mold sections are parted to urge the ejector ring toward the other mold section and engage a peripheral portion of the target to strip or eject the target from the associated mold section without distortion. At the same time, the ejector ring is designed to supply air between the target and the associated mold section to prevent a vacuum from forming therebetween. This facilitates ejection and increases the ejection rate.

It is, therefore, a principal object of the invention to provide an improved ejecting mechanism for a frangible flying target fonning machine having the advantages discussed above.

Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings, in which:

H6. 11 is a fragmentary plan view, with parts broken away and with parts in section, of a multistation target forming machine embodying the invention;

FIG. 2 is a fragmentary view in elevation of the machine of FIG. i;

FIG. 35 is an enlarged view in vertical cross section taken along the line 3-3 of MG. 2;

Fit 4 is a view in vertical cross section similar to FlG. 3, but taken along the line M of FIG. 2;

FIG. 5 is a view in horizontal cross section taken along the line E-5 of H6. 3; and

FIG. 6 is an enlarged view in cross section taken along the line M of H6. 1.

Referring to H68. 11 and 2, a 32 station frangible flying target forming machine is indicated at 10, with only a few of the stations shown. The overall machine it is of a known, com mercially available design and will not be discussed in detail. Briefly, in the operation of the machine, the target mold cavities are filled with a carefully controlled, predetermined weight of a moldable compound for producing the targets. The moldable compound mainly consists of a tar substance which is inexpensive and yet produces the proper frangible characteristics for the formed target. After the moldable compound is supplied to the cavity at approximately 450 F., the mold sections are brought together and proceed through a circular path during which time cold water can be applied supplied through suitable passages in the mold sections to hasten the cooling and hardening of the molding compound. However, when ejected from the mold cavity, the target is not fully hardened and care must be taken to avoid distortion or damage at this time.

The machine includes 32 mold or die assemblies l2 mounted on a turntable M and an upper support 16, each assembly 12 including a lower mold unit 28 and an upper mold unit 29. The lower unit lid includes a lower mold or die section 22 forming a recess 24 for the convex surface of a target 26. A large knock-out pin 28 extends through the mold section 22 and shapes the central portion of the target 26. The knock-out pin 2% can be moved upwardly at the proper time, as shown in MG. 2, as by an air cylinder 29 or a cam (not shown) mounted therebelow, to push the target 26 out of the recess 24.

The upper mold unit 20 includes a mold or die section 30 extending into the recess 24 when the units l8 and 2d are assembled and forming a convex mold surface 32 which shapes the concave surface of the target. The mold section 30 also forms a cylindrical portion 33 extending upwardly to a shoulder M and an enlarged cylindrical portion 36 having an O-ring 3&The section 30 is mounted on a heavy backup or supporting plate 30 by bolts 2. The two mold units 18 and 20 are equipped with suitable, conventional passages for cold water, which are not shown for clarity of illustration.

ln accordance with the invention, an ejector ring 44$ is located around the mold section 30 and mounted for movement toward and away from the lower mold section 22. The ejector ring 44 has a lower annular edge 4b which actually forms part of the mold cavity and shapes a peripheral edge dial of the target as. The ejector ring 44 also engages the peripheral edge 41% when the lower and upper units 18 and 2t) begin to separate and the ejector ring 44 is moved downwardly relative to the upper mold section 30. This provides a uniform peripheral force on the target 26 which avoids any distortion thereof or damage thereto. Since the edge 46 of the ring 44 actually shapes the peripheral edge 48 which it subsequently engages for ejection, uniform pressure is applied over the entire edge so that no surface damage will result during the ejecting or stripping process.

The ejector ring 44 has an upper enlarged cylindrical recess 50 cooperating with theenlargement 36 and the O-ring 38. The ring also forms a smaller cylindrical passage 52 with a beveled shoulder 54 located between the passage 52 and the enlarged recess 56 A supply opening or passage 56 supplies fluid, preferably air, to the space between the shoulders 34 and 5d, thereby to urge the ring 44$ downwardly and effect the ejection of the target 26 from the mold section 39. The air can be supplied as the units 318 and 26) separate so that the ring will remain stationary, in effect, as the mold section 3t rises, as shown in FlG. during the initial upward movement of the unit 2%.

Also in accordance with the invention, as air is supplied to the space between the shoulders 34 and 5d, a portion of the air also will flow downwardly through an annular space between the cylindrical shank portion 33 of the mold section Elli and the cylindrical passage 52 of the ring 44. The air flowing through the annular space is important in that it enters the void formed between the target 26 and the mold section 30 as they separate, thereby eliminating a vacuum and facilitating ejection. The diameters of the respective shank portion and passage are design-led so that an annular space of a predetermined thickness is formed therebetween. Preferably, the shank portion 33 will have a diameter from 0.005 inch to 0.015 inch less than the diameter of the cylindrical passage 52, to provide the proper clearance or annular space. If the space is too thin, sufficient air will not flow through it. if the space is too wide, then the molding compound will tend to enter and cause plugging.

The ring id is supported relative to the bacltup plate ill by shoulder bolts 5%, springs oh, and washers 62, the springs seating in recesses M. The springs as normally urge the ring 44!- sgainst the backup plate dd until air is supplied through the passage do. With this arrangement, when the lower and upper units Rd and 2d are in their assembled relationship, as shown in MG. 3, the lower edge portion as of the ring seats firmly against the periphery of the mold section 22 which can be beveled, as shown, to assure centering of the ring 44 and the upper mold unit relative to the lower mold unit 18. Further, with the ring 44 rigidly backed-up by the plate 40, it will exert pressure on the lower mold section 22 to minimize the possibility of molding compound flowing between the ring 44 and the lower mold section 22 and producing undesirable flash on the target 26.

Air can be supplied to the passage 56 automatically when the assembly 12 reaches a station at which ejection is to begin. For this purpose, a flexible line 66 is connected at one end to the ring 44 in communication with the passage 56. The other end of the line 66 is connected to a central distributing ring 68 in communication with a passage 70 (FIG. 6) therein. The passage 70 connects to a radially extending passage 72 which opens at an outer surface 74 of the distributing ring 68. A main air supply 76 is connected to a supply housing 78 and communicates with a central passage 80 therein. The housing 78 is supported through a bracket 82, which extends upwardly, and is urged by a spring 84 against the face 74 of the ring 68 and automatically supplies air to the line 66 whenever the passages 72 and 80 are in alignment. Such alignment occurs when the assembly 12 reaches a predetermined point or station on the circular path at which ejection of the target 26 is initiated.

Various modifications of the above described embodiment of the invention will be apparent to those skilled in the art and it is to be understood that such modifications can be made without departing from the scope of the invention, the embodiment shown and described being primarily for purposes of illustration and not limitation.

lclaim:

1. A multisection mold forming a cavity and including a stripper mechanism, said mechanism comprising an ejector member mounted about one of said mold sections, means for supplying fluid under pressure to said ejector member to urge said ejector member toward a mold product in the cavity after the mold sections are separated, and passage means for supplying a portion of the fluid under pressure between the mold product and said one mold section.

2. A mold according to claim 1 characterized further by a rigid support associated with said one mold section, and resilient means urging said ejector member toward said support.

3. A mold according to claim 1 characterized by said passage means being disposed between said ejector member and said one mold section.

4. A mold according to claim characterized by said ejector member being a ring positioned around said one mold section and effective to contact a peripheral portion of the mold product in the cavity.

5. Apparatus for producing frangible targets comprising a two section mold including a concave section and a convex section, the latter extending into the former, an ejector ring positioned around said convex mold section and forming an annular ejector edge around said convex mold section, said ejector ring being movable toward and away from said concave mold section, means for supplying air under pressure to said ejector ring to urge said ejector ring toward said concave mold section, said convex mold section and said ring being constructed to direct a portion of the air under pressure between a target and said convex mold section when the two mold sections are separated.

6. Apparatus according to claim 5 characterized by a rigid support associated with said convex mold section, and resilient means urging said ejector ring toward said support.

7. Apparatus according to claim 5 characterized by said convex mold section having a cylindrical portion and said ring having a cylindrical passage located adjacent said cylindrical portion, said cylindrical portion being smaller than said cylindrical passage to form an annular space therebetween through which the portion of the air under pressure is directed.

8. Apparatus according to claim 5 characterized further by said annular ejector edge of said ejector ring forming part of the mold cavity between said'mold sections and shaping a peripheral edge of the frangible target. 

